一、前言

我们后端开发中，时常需要用到文件上传的功能，无非是保存到服务器本地或者如阿里云、七牛云这种云存储的方案。本篇介绍一种使用后台springboot结合前端vue实现阿里云oss上传的功能。

二、前端实现过程

前端实现一个通用的上传组件UploadFile

<template><div class="upload-file"><el-upload:multiple="multiple":accept="accept.join(',')":action="uploadFileUrl":before-upload="handleBeforeUpload":file-list="fileList":limit="limit":on-error="handleUploadError":on-exceed="handleExceed":on-success="handleUploadSuccess":show-file-list="false":data="data":headers="headers"class="upload-file-uploader"ref="fileUpload"><!-- 上传按钮 --><el-button size="mini" type="primary">选取文件</el-button><template v-if="multiple"> （按住Ctrl键多选）</template><!-- 上传提示 --><div class="el-upload__tip" slot="tip" v-if="showTip && fileList.length<=0">请上传<template v-if="limit"> 最多 <b style="color: #f56c6c">{{ limit }}个</b></template><template v-if="fileSize"> 大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b></template><template v-if="fileType"> 格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b></template>的文件</div></el-upload><!-- 文件列表 --><transition-group class="upload-file-list el-upload-list el-upload-list--text" name="el-fade-in-linear" tag="ul" height="485"><li v-for="(file, index) in fileList" :key="file.uid || index "class="el-upload-list__item ele-upload-list__item-content"><el-link :href="file.url" :underline="false" target="_blank"><span class="el-icon-document"> {{ file.name }} </span></el-link><div class="ele-upload-list__item-content-action"><el-link :underline="false" @click="handleDelete(index)" type="danger" style="width: 50px">删除</el-link></div></li></transition-group></div>
</template><script>
import {getToken} from "@/utils/auth";export default {name: "FileUpload",props: {// 是否可多选multiple: {type: Boolean,default: true,},// 值value: [String, Object, Array],// 数量限制limit: {type: Number,default: 5,},// 大小限制(MB)fileSize: {type: Number,default: 5,},// 文件类型, 例如['png', 'jpg', 'jpeg']fileType: {type: Array,default: () => ["doc", "xls", "xlsx", "ppt", "txt", "pdf"],},accept: {type: Array,default: () => [".doc", ".xls", ".xlsx", ".ppt", ".txt", ".pdf"],},// 是否显示提示isShowTip: {type: Boolean,default: true},// 是否重命名rename: {type: Boolean,default: false}},data() {return {number: 0,uploadList: [],uploadFileUrl: process.env.VUE_APP_BASE_API + "/file/upload", // 上传文件服务器地址headers: {Authorization: "Bearer " + getToken(),},fileList: [],data: {}};},watch: {value: {handler(val) {if (val) {let temp = 1;// 首先将值转为数组const list = Array.isArray(val) ? val : this.value.split(',');// 然后将数组转为对象数组this.fileList = list.map(item => {if (typeof item === "string") {item = {name: item.name, url: item.url};}item.uid = item.uid || new Date().getTime() + temp++;return item;});} else {this.fileList = [];return [];}},deep: true,immediate: true},rename: {handler(val) {this.data = {rename: val}console.info(this.data)},deep: true,immediate: true}},computed: {// 是否显示提示showTip() {return this.isShowTip && (this.fileType || this.fileSize);},},methods: {// 上传前校检格式和大小handleBeforeUpload(file) {// 校检文件类型if (this.fileType) {const fileName = file.name.split('.');const fileExt = fileName[fileName.length - 1];const isTypeOk = this.fileType.indexOf(fileExt) >= 0;if (!isTypeOk) {this.$modal.msgError(`文件格式不正确, 请上传${this.fileType.join("/")}格式文件!`);return false;}}// 校检文件大小if (this.fileSize) {const isLt = file.size / 1024 / 1024 < this.fileSize;if (!isLt) {this.$modal.msgError(`上传文件大小不能超过 ${this.fileSize} MB!`);return false;}}this.$modal.loading("正在上传文件，请稍候...");this.number++;return true;},// 文件个数超出handleExceed() {this.$modal.msgError(`上传文件数量不能超过 ${this.limit} 个!`);},// 上传失败handleUploadError(err) {this.$modal.msgError("上传文件失败，请重试");this.$modal.closeLoading()},// 上传成功回调handleUploadSuccess(res, file) {if (res.code === 200) {this.uploadList.push({name: res.data.name, url: res.data.url});this.uploadedSuccessfully();} else {this.number--;this.$modal.closeLoading();this.$modal.msgError(res.msg);this.$refs.fileUpload.handleRemove(file);this.uploadedSuccessfully();}},// 删除文件handleDelete(index) {this.fileList.splice(index, 1);this.$emit("input", this.listToString(this.fileList));},// 上传结束处理uploadedSuccessfully() {if (this.number > 0 && this.uploadList.length === this.number) {this.fileList = this.fileList.concat(this.uploadList);this.uploadList = [];this.number = 0;this.$emit("input", this.listToString(this.fileList));this.$modal.closeLoading();}},// 获取文件名称getFileName(name) {if (name.lastIndexOf("/") > -1) {return name.slice(name.lastIndexOf("/") + 1);} else {return "";}},// 对象转成指定字符串分隔listToString(list, separator) {let strs = "";separator = separator || ",";for (let i in list) {strs += list[i].url + separator;}return strs != '' ? strs.substr(0, strs.length - 1) : '';}}
};
</script><style scoped lang="scss">
.upload-file-uploader {margin-bottom: 5px;
}.upload-file-list {max-height: 420px;overflow-y: auto;
}.upload-file-list .el-upload-list__item {border: 1px solid #e4e7ed;line-height: 2;margin-bottom: 10px;position: relative;
}.upload-file-list .ele-upload-list__item-content {display: flex;justify-content: space-between;align-items: center;color: inherit;
}.ele-upload-list__item-content-action .el-link {margin-right: 10px;
}
</style>

使用示例

<template><div class="app-container"><el-dialog title="附件上传" :visible.sync="open" width="700px" append-to-body><el-form ref="form" :model="form" :rules="rules" label-width="100px">        <el-form-item label="重命名附件" prop="rename"><el-radio-group v-model="form.rename"><el-radio :label="false">否</el-radio><el-radio :label="true">是</el-radio></el-radio-group></el-form-item><el-form-item label="上传附件" prop="file" class="is-required"><!-- 文件大小最多20M，数量最多20个 --><file-upload ref="upload" :fileType="fileType" :accept="accept" :fileSize="20" :limit="20" :value="form.files" :rename="form.rename"/></el-form-item></el-form><div slot="footer" class="dialog-footer"><el-button type="primary" @click="submitForm">确 定</el-button><el-button @click="cancel">取 消</el-button></div></el-dialog></div>
</template><script>
import { add } from "@/api/xxx"; // 请求后台的接口封装
import FileUpload from "@/components/FileUpload";
export default {name: "demo",components: {FileUpload},data() {return {// 自定义允许上传的文件格式，也可以使用组件里面定义的默认格式fileType: ['png','jpg','jpeg','gif'],accept: ['.png','.jpg','.jpeg','.gif'],// 表单参数form: {// 是否重命名rename: false,files: []},// 表单校验rules: {files: [{type: 'array', required: true, message: "附件不能为空", trigger: "blur"}]}}},methods: {/** 提交按钮 */submitForm: function () {this.$refs["form"].validate(valid => {if (valid) {this.form.files = this.$refs.upload.fileListif (!Array.isArray(this.form.files) || this.form.files.length <= 0) {this.$alert("请上传附件");return false;}console.info(this.form)add(this.form).then(() => {this.$modal.msgSuccess("操作成功");this.open = false;});}});},            ...}
}
</script>

效果如下

文件选中后会立即上传，上传之后的效果如下

上传完后，后端返回的文件url可以跟其他表单字段一起保存到数据库。

三、后端实现过程

springboot后端实现逻辑

/*** 文件上传请求*/
@PostMapping("/upload")
public Result upload(MultipartFile file, @RequestParam(required = false) Boolean rename) {try {SysFile sysFile = ossService.upload(file, rename);return Result.success(sysFile);} catch (Exception e) {log.error("上传文件失败", e);return Result.fail(e.getMessage());}
}

/*** 文件上传请求*/
@Override
public SysFile upload(MultipartFile file, Boolean rename) throws IOException {// 获取文件名String fileName = file.getOriginalFilename();if (rename != null && rename) {// 重命名Long fileFlag = new SnowFlakeGenerator().nextId();fileName = fileFlag + "." + FileTypeUtils.getExtension(file);}String uri = String.format("file/%s", fileName);// 上传到文件服务byte[] bytes = file.getBytes();// 上传并返回访问地址if (!this.upload(uri, bytes)) {throw new ServerErrorException("上传失败");}String filePath = String.format("%s/%s", "阿里云OSS地址", uri);SysFile sysFile = new SysFile();sysFile.setName(fileName);sysFile.setUrl(filePath);return sysFile;
}private Boolean upload(String fileId, byte[] bytes) {InputStream in = null;try {in = new ByteArrayInputStream(bytes);return this.upload(fileId, in);} finally {if (in != null) {try {in.close();} catch (IOException e) {}}}
}private Boolean upload(String key, InputStream in) {OSSClient client = getOSSClient();try {ObjectMetadata objectMetadata = null;//文本文件特殊处理if (key.endsWith(".txt")) {objectMetadata = new ObjectMetadata();// 设置content typeobjectMetadata.setContentType("txt/plain;charset=utf-8");}PutObjectResult result = client.putObject(config.getBucketName(), key, in, objectMetadata);ResponseMessage response = result.getResponse();log.info("Oss upload result:{}", response.isSuccessful());return response.isSuccessful();} catch (OSSException oe) {log.error(oe.getErrorMessage());return false;} catch (ClientException ce) {log.error(ce.getErrorMessage());return false;} finally {client.shutdown();}
}private OSSClient getOSSClient() {// config--阿里云oss的配置信息，略return (OSSClient) new OSSClientBuilder().build(config.getEndPoint(), config.getKeyId(), config.getSecret());
}

pom.xml

<!-- Aliyun oss -->
<dependency><groupId>com.aliyun.oss</groupId><artifactId>aliyun-sdk-oss</artifactId><version>3.10.2</version>
</dependency>

到这里功能差不多就结束了。如果对你有帮助，请关注+点赞